<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>

        while (true){
            var score = prompt('请输入小明得期末成绩(0,100)')
            if (score<=100 && score>=0){
                break
            }
            alert('请重新输入')
        }

        if (score > 100 || score < 0 || isNaN(score)){
            alert('别特么瞎吹牛逼')
        } else {
            if (score == 100){
            alert('给你一个宝马');
            } else if (80 <= score && score < 100){
                alert('水果手机给你');
            } else if (60 <= score && score < 80){
                alert('给你一本书好好学习吧');
            } else if (score >=0 && score < 60){
                alert('你真是个彩笔');
            }
        }



    </script>
</head>
<body>

</body>
</html>